In this subpart—

Full-time service means service performed by an employee who has—

An officially established recurring basic workweek consisting of 40 hours within the employee's administrative workweek (as established under § 610.111 of this chapter or similar authority);

An officially established recurring basic work requirement of 80 hours per biweekly pay period (as established for employees with a flexible or compressed work schedule under 5 U.S.C. chapter 61, subchapter II, or similar authority);

For a firefighter covered by 5 U.S.C. 5545b(b) who does not have a 40-hour basic workweek, a regular tour of duty averaging at least 106 hours per biweekly pay period; or

A work schedule that is considered to be full-time by express provision of law, including a work schedule established for certain nurses under 38 U.S.C. 7456 or 7456A that is considered by law to be a full-time schedule for all purposes.

Part-time service means any actual service performed on a less than full-time basis, by an individual whose appointment describes a regularly scheduled tour of duty, and any period of time credited as nonpay status time under 5 U.S.C 8411(d), that follows a period of part-time service without any intervening period of actual service other than part-time service.

Proration factor means a fraction expressed as a percentage rounded to the nearest percent. The numerator is the sum of the number of hours the employee actually worked during part-time service; and the denominator is the sum of the number of hours that a full-time employee would be scheduled to work during the same period of service included in the numerator. If an employee has creditable service in addition to part-time service, such service must be included in the numerator and denominator of the fraction.

Total service means the full years and twelfth parts thereof of an employee's or Member's service creditable under subpart C of this part, excluding any fractional part of a month.